Below is a clear, SAP-consultant level comparison of MD04 vs MD05 vs MRP Live, focused on how they work, data sources, and when to use what—especially relevant in S/4HANA 2021+ / 2023.

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🔷 1. MD04 – Stock / Requirements List

(Material-centric, real-time view)

Purpose

Shows current stock, demands, and supplies for ONE material + plant.

Key Characteristics

• 📌 On-the-fly calculation
• 📌 No MRP run required
• 📌 Used for day-to-day operational checks
• 📌 Interactive (convert planned orders, firming, rescheduling)

Data Source

• Real-time reads from:
  • Transactional tables (PLAF, VBBE, EKET, AFPO, etc.)
  • MRP buffer tables (MDKP, MDTB – logical)
• Uses function modules like:
  • MD_STOCK_REQUIREMENTS_LIST_API

Typical Use

✔ Planner checking availability
✔ ATP / shortage analysis
✔ Manual adjustments

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🔷 2. MD05 – MRP List

(MRP-run result snapshot)

Purpose

Shows results of the LAST MRP RUN for one material + plant.

Key Characteristics

• 📌 Snapshot, not real-time
• 📌 Only updated after MRP execution
• 📌 Used for planner worklists
• 📌 Can differ from MD04 if data changed after MRP

Data Source

• Purely MRP result tables
  • MDKP – Header
  • MDTB – Planning elements
• No recalculation at display time

Typical Use

✔ Analyze MRP proposals
✔ Planning exception messages
✔ Controlled planning environment

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🔷 3. MRP Live (HANA-Based)

(High-performance, database-driven MRP)

Purpose

Mass MRP execution using HANA push-down logic.

Transactions

Function	T-Code
Single material	MD01N
Plant MRP	MD01
MRP Live config	OM0F
MRP Live monitor	Fiori MRP apps

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🚀 How MRP Live is Different

Area	Classic MRP	MRP Live
Logic	ABAP-heavy	SQLScript / HANA
Tables	MDKP / MDTB	No MRP tables written
Speed	Slow for large volumes	10–100x faster
Parallelization	Limited	Native HANA
Exceptions	Post-processing	Inline

📌 MRP Live reads MATDOC, MARC, PLAF, VBBE, EKET, etc.
📌 Results are not stored → recalculated each run.

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🔷 Relationship Between the Three

Scenario	What You See
Run Classic MRP → MD05	Exact MRP run snapshot
Run Classic MRP → MD04	Near-real-time + MRP results
Run MRP Live → MD05	❌ MD05 usually empty
Run MRP Live → MD04	✔ Recalculated live view

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🔥 Key Consultant-Level Differences (Exam / Interview Ready)

Topic	MD04	MD05	MRP Live
Real-time	✔	❌	✔
Stores results	❌	✔	❌
Depends on MRP run	❌	✔	❌
Uses MDKP/MDTB	Logical	Physical	❌
Performance	Medium	Fast	🚀 Very Fast
HANA-optimized	Partial	❌	✔

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🎯 When to Use What

• MD04 → Operational planning & execution
• MD05 → MRP analysis & exception handling
• MRP Live → High-volume, high-speed planning in S/4